Lots of ways to do that. The question is which means works best for this application. But then you have not told us anything about this application except the input and the output.
The idea to look into block and tackle design is a good one, and the most obvious. But by the time you figure in friction you are probably looking at 20 parts of line or more. That many parts creates other problems that might drive you to a different lifting method. This is the point where more details would be useful.
Hi I am building an electric bicycle and I want to use a high rpm(6-8000 rpm) brushless motor. the gear reducers I've found have not been able to hande more than about 4000rpm. I was wondering if anyone has heard of using a tesla turbine as a sort of reduction/torque convertor. My idea is to make something that looks like a clutch with input and output disks stacked and sandwiched with low tolerance in some sort of viscous oil and use the surface cohesion to transfer torque. In my mind the molecules of oil would roll against eachother and create a kind of planetary like reduction. Is that completely ridiculous?